scholarly journals CircEIF4G2 Promotes Tumorigenesis and Progression of Osteosarcoma by Sponging miR-218

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Erhu Lin ◽  
Shuai Liu ◽  
Wei Xiang ◽  
Hongbo Zhang ◽  
Chaofan Xie

Circular RNAs (circRNAs) play a key role in regulating the tumorigenesis and development of human cancers, including osteosarcoma (OS). Of note, the molecular mechanism underlying the progression of OS has remained largely unclear. The present study identified that a novel circRNA circEIF4G2 was upregulated in OS tissues and cells. Moreover, we constructed a circEIF4G2-mediated ceRNA network and revealed that circEIF4G2 was involved in regulating multiple cancer pathways, such as the EGFR signaling pathway, the PI3K-Akt signaling pathway, and the ErbB signaling pathway. Loss-of-function assays showed that circEIF4G2 knockdown significantly suppressed OS cell proliferation, migration, and invasion. Mechanically, we found that circEIF4G2 could directly bind to miR-218, and miR-218 mediated the effect of circEIF4G2 knockdown on OS progression. In conclusion, the present study showed that circEIF4G2 could be a potential biomarker for OS.

Author(s):  
Xuehui Wang ◽  
Changle Ji ◽  
Jiashu Hu ◽  
Xiaochong Deng ◽  
Wenfang Zheng ◽  
...  

Abstract Background Circular RNAs (circRNAs), a novel class of endogenous RNAs, have shown to participate in the development of breast cancer (BC). Hsa_circ_0005273 is a circRNA generated from several exons of PTK2. However, the potential functional role of hsa_circ_0005273 in BC remains largely unknown. Here we aim to evaluate the role of hsa_circ_0005273 in BC. Methods The expression level of hsa_circ_0005273 and miR-200a-3p were examined by RT-qPCR in BC tissues and cell lines. The effect of knocking down hsa_circ_0005273 in BC cell lines were evaluated by examinations of cell proliferation, migration and cell cycle. In addition, xenografts experiment in nude mice were performed to evaluate the effect of hsa_circ_0005273 in BC. RNA immunoprecipitation assay, RNA probe pull-down assay, luciferase reporter assay and fluorescence in situ hybridization were conducted to confirm the relationship between hsa_circ_0005273, miR-200a-3p and YAP1. Results Hsa_circ_0005273 is over-expressed in BC tissues and cell lines, whereas miR-200a-3p expression is repressed. Depletion of hsa_circ_0005273 inhibited the progression of BC cells in vitro and in vivo, while overexpression of hsa_circ_0005273 exhibited the opposite effect. Importantly, hsa_circ_0005273 upregulated YAP1 expression and inactivated Hippo pathway via sponging miR-200a-3p to promote BC progression. Conclusions Hsa_circ_0005273 regulates the miR-200a-3p/YAP1 axis and inactivates Hippo signaling pathway to promote BC progression, which may become a potential biomarker and therapeutic target.


2021 ◽  
Vol 11 (8) ◽  
pp. 1466-1476
Author(s):  
Xuli Wang ◽  
Aiping Wang

Circular RNAs (circRNAs) have been reported to participate in the molecular mechanism of human cancers. This study investigates the role of circRNA hsa_circ_0000515 in gastric cancer (GC) cells and the underlying mechanism associated with microRNA-615-5p (miR-615-5p). qRT-PCR analysis showed the upregulation of hsa_circ_0000515 and downregulation of miR-615-5p in GC cell lines. Loss-of-function experiments indicated that suppression of hsa_circ_0000515 inhibited cell proliferation, migration, and invasion. Dual-luciferase reporter assay highlighted that hsa_circ_0000515 was able to act as a ceRNA of miR-615-5p. Furthermore, hsa_circ_0000515 could interact with splicing factors and bind miR-615-5p to regulate progression of GC cells. Deficiency of miR-615-5p reverses the inhibitory roles of si-hsa_circ_0000515 on the proliferation, migration, and invasion of GC cells. The findings highlighted the promising uses of hsa_circ_0000515 as a likely novel target for gastric cancer treatment.


2018 ◽  
Vol 46 (3) ◽  
pp. 1286-1304 ◽  
Author(s):  
Min Xu ◽  
Dong Li ◽  
Chen Yang ◽  
Jian-Song Ji

Background/Aims: Breast cancer (BC) starts as a local disease, but it can metastasize to the lymph nodes and distant organs. However, the metastatic process is still poorly understood. The mRNA microarray datasets GSE26910 and GSE33447 show that CXCL10 is up-regulated in BC, and the microRNA microarray dataset GSE38167 and a network meta-analysis of microRNA expression profile studies in human BC suggest that microRNA-34a (miR-34a) is down-regulated in BC. CXCL10 was predicted as a target of miR-34a by microRNA.org. In this study, we uncovered a CXCL10-independent mechanism by which miR-34a exerts its antimetastatic activity in BC. Methods: To investigate the clinical significance of miR-34a in BC, we collected cancer tissues and paracancerous tissues from 258 patients with BC. In addition, a series of inhibitors, mimics, and siRNAs was introduced into MCF-7 and T47D cells to validate the regulatory mechanisms by which miR-34a regulates CXCL10. Next, to better understand the pivotal role of TLR signaling pathway inhibition in MCF-7 and T47D cells, we blocked the TLR signaling pathway using OxPAPC, an antagonist of TLR signaling. Results: Among BC patients, miR-34a was down-regulated, CXCL10 was up-regulated, and the TLR signaling pathway was activated. Determination of luciferase activity revealed that CXCL10 was a target of miR-34a. Through gain- and loss-of-function studies, miR-34a was demonstrated to negatively regulate CXCL10; inhibit activation of the TLR signaling pathway; significantly suppress in vitro cell proliferation, migration, and invasion; and induce apoptosis. Conclusion: Our findings suggest that functional loss or suppression of the tumor suppressor CXCL10 due to induction of miR-34a leads to inhibition of the TLR signaling pathway during breast tumorigenesis, providing a novel target for the molecular treatment of breast malignancies.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Juan Cai ◽  
Zhiqiang Chen ◽  
Xueliang Zuo

Background. Circular RNAs have been implicated in various malignancies and can function as potential biomarkers for cancers. Reportedly, circSMARCA5 was downregulated in hepatocellular carcinoma and glioblastoma multiforme, but upregulated in prostate cancer. The functional roles and clinical significance of circSMARCA5 still remain unknown in the context of gastric cancer (GC). Methods. Expression levels of circSMARCA5 were detected by qRT-PCR. Clinical data including patient basic information, clinicopathological features, and survival data were obtained. The Kaplan-Meier methods, multivariate Cox regression models, and the receiver operating characteristic curve were used to assess the clinical significance of circSMARCA5 in GC. Cell proliferation assays and transwell assays were performed to elucidate the functional roles of circSMARCA5 in GC. Results. The circSMARCA5 level was decreased in GC tissues and cell lines. The low expression level of circSMARCA5 was correlated to poorer overall survival and disease-free survival. Low circSMARCA5 expression was revealed as an independent unfavorable predictive factor for GC. The results indicated that circSMARCA5 had a moderate ability for discrimination between GC patients and controls with an area under the curve of 0.806. Upregulation of circSMARCA5 dampened the proliferation, migration, and invasion of GC cells, whereas circSMARCA5 knockdown promoted GC progression. Discussion. Our results demonstrated that circSMARCA5 was decreased and exerted tumor-suppressive effects in GC. circSMARCA5 can function as a potential biomarker for GC prognosis and diagnosis.


Author(s):  
Shan Lei ◽  
Zhiwei He ◽  
Tengxiang Chen ◽  
Xingjun Guo ◽  
Zhirui Zeng ◽  
...  

Abstract Background Accumulation evidence indicates the vital role of long non-coding RNAs (lncRNAs) in tumorigenesis and the progression of malignant tumors, including pancreatic cancer (PC). However, the role and the molecular mechanism of long non-coding RNA 00976 is unclear in pancreatic cancer. Methods In situ hybridization (ISH) and qRT-PCR was performed to investigate the association between linc00976 expression and the clinicopathological characteristics and prognosis of patients with PC. Subsequently, linc00976 over-expression vector and shRNAs were transfected into PC cells to up-regulate or down-regulate linc00976 expression. Loss- and gain-of function assays were performed to investigate the role of linc00976 in proliferation and metastasis in vitro and vivo. ITRAQ, bioinformatic analysis and rescue assay were used to illustrate the ceRNA mechanism network of linc00976/miR-137/OTUD7B and its downstream EGFR/MAPK signaling pathway. Results linc00976 expression was overexpressed in PC tissues and cell lines and was positively associated with poorer survival in patients with PC. Function studies revealed that linc00976 knockdown significantly suppressed cell proliferation, migration and invasion in vivo and in vitro, whereas its overexpression reversed these effects. Based on Itraq results and online database prediction, Ovarian tumor proteases OTUD7B was found as a downstream gene of linc00976, which deubiquitinated EGFR mediates MAPK signaling activation. Furthermore, Bioinformatics analysis and luciferase assays and rescue experiments revealed that linc00976/miR137/OTUD7B established the ceRNA network modulating PC cell proliferation and tumor growth. Conclusion The present study demonstrates that linc00976 enhances the proliferation and invasion ability of PC cells by upregulating OTUD7B expression, which was a target of miR-137. Ultimately, OTUD7B mediates EGFR and MAPK signaling pathway, suggesting that linc00976/miR-137/OTUD7B/EGFR axis may act as a potential biomarker and therapeutic target for PC.


2019 ◽  
Author(s):  
Xue Bai ◽  
Chunyang Zheng ◽  
Na Ren

ABSTRACTOBJECTIVETo investigate the effect of the miR-195/EGFR signaling pathway on trophoblasts in patients with recurrent spontaneous abortion, thus providing a clinical basis for the diagnosis and treatment of recurrent spontaneous abortion.METHODSRT-qPCR, western blot, flow cytometry, CCK8, cell scratch assay, transwell, and a dual Luciferase reporter assay were used to detect changes in the miR-195/EGFR signaling pathways in clinical samples and in vitro cultured cells and to explore how these changes affect trophoblasts in affected patients.RESULTSExpression of miR-195 was elevated in villus tissues of patients with recurrent spontaneous abortion, while the expression levels of EGFR and its downstream genes p38 and AKT phosphorylation were down-regulated. In vitro cultured cell experiments showed that miR-195 inhibited the proliferation, migration, and invasion of trophoblast cells. EGFR is a target gene of miR-195, and miR-195 suppresses the expression of EGFR.ConclusionThe miR-195/EGFR signaling pathway regulates the proliferation, migration, and invasion of trophoblast cells, thus playing an important role in recurrent spontaneous abortion.


Author(s):  
Hao Shi ◽  
Shan Huang ◽  
Mingde Qin ◽  
Xiaofeng Xue ◽  
Xingpo Guo ◽  
...  

Cancer-associated fibroblast (CAF)-derived exosomes play a major role in gastric carcinoma (GC) tumorigenesis. However, the mechanism behind the activity of circular RNAs in CAF-derived exosomes in GC remains unclear. In the present study, we identified differentially expressed circ_0088300 in GC tissues and plasma exosomes. We found that CAFs delivered functional circ_0088300 to GC tumor cells via exosomes and promoted the proliferation, migration and invasion abilities of GC cells. Furthermore, we demonstrated that circ_0088300 packaging into exosomes was driven by KHDRBS3. In addition, we verified that circ_0088300 served as a sponge that directly targeted miR-1305 and promoted GC cell proliferation, migration and invasion. Finally, the JAK/STAT signaling pathway was found to be involved in the circ_0088300/miR-1305 axis, which accelerates GC tumorigenesis. In conclusion, our results indicated a previously unknown regulatory pathway in which exosomal circ_0088300 derived from CAFs acts as a sponge of miR-1305 and promotes GC cell proliferation, migration and invasion; these data identify a potential biomarker and novel therapeutic target for GC in the future.


2021 ◽  
Author(s):  
Weiqian Chen ◽  
Liyun Zheng ◽  
Songquan Wu ◽  
Chenying Lu ◽  
Bufu Tang ◽  
...  

Abstract Background: Cholangiocarcinoma (CCA) is an aggressive malignancy with a poor prognosis, with no effective therapy other than surgical resection. Circular RNAs (circRNAs) serve as a brand-new class of transcription products among abundant cancer processes. Nevertheless, the mechanisms account for their modification in CCA remain unknown. Methods: First, microarray sequencing was applied to detect the difference of circRNAs expression between CCA and corresponding non-tumor tissues. We utilized qRT-PCR to measure circ-0006302 levels in CCA cells and specimens. Gain/loss of-function assays and animal model of CCA were performed for the purpose of revealing the functions of circ-0006302 on the invasion, migration, and proliferation of CCA. We performed dual luciferase reporter, RNA-FISH and rescue assays for clarifying the mechanism behind. Results: In CCA tissues and cell lines circ-0006302 was highly expressed relatively. In vitro, overexpression of circ-0006302 intensifies the epithelial-to-mesenchymal transition (EMT) and the invasion, migration, and growth of CCA cells; and intensifies the growth as well as metastasis of tumors in a CCA mouse model. Furthermore, it was elucidated that circ-0006302 sponged miR-1299 to upregulate PD‐L1 expression. Through the process above, circ-0006302 binds to miR-1299 and emancipates PD-L1, facilitating the invasion, migration, and proliferation in CCA cells. Momentously, the results obtained revealed that circ-0006302 silencing elevated the expression of interferon (IFN)‐γ, and interleukin (IL)‐4 but diminished the IL-10 expression, while these effects could be reversed by miR-1299 inhibitor.Conclusion: circ-0006302 silence blocked the CCA progression via intensifying miR‐1299‐targeted downregulation of PD‐L1. Our conclusion provides novel therapeutic tactics for treating this fatal disease.


2018 ◽  
Vol 61 (8) ◽  
pp. 893-901 ◽  
Author(s):  
Qian Liu ◽  
Junwen Zhang ◽  
Hua Gao ◽  
Taoyang Yuan ◽  
Jie Kang ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Kun Huang ◽  
Ningning Gao ◽  
Donglin Bian ◽  
Qixi Zhai ◽  
Puxu Yang ◽  
...  

Epithelial-mesenchymal transition (EMT) plays an important role in the invasion and metastasis of colorectal cancer, which is mediated by FAK and EGF. However, whether FAK participates in EMT in colorectal cancer cells through the EGF/EGFR signaling pathway remains unknown. The aim of this study was to investigate the effector mechanisms of FAK in the process of EGF-induced EMT in colorectal cancer cells and to determine whether miR-217 is involved in this process. Caco-2 cancer cells were routinely cultured with and without treatment with 100 ng/mL EGF, and changes in cell morphology were observed using an inverted microscope. In addition, a transwell assay was used to detect cell migration under the condition of EGF treatment. The expression of FAK, pFAK, E-cadherin, vimentin, and β actin was assessed by western blotting, and the expression of miR-217 was assessed using real-time PCR. We found that EGF induced EMT in colorectal cancer cells and enhanced cell migration and invasion ability. Moreover, FAK was involved in the EGF-induced EMT of colorectal cancer cells. EGF upregulated the expression of E-cadherin in colorectal cancer cells by activating FAK, and miR-217 was found to participate in EGF-induced EMT in colorectal cancer cells. Our findings indicate that EGF induces EMT in colorectal cancer cells by activating FAK, and miR-217 is involved in the EGF/FAK/E-cadherin signaling pathway.


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